1. Field of the Invention
The present invention relates to locking devices, and particularly to a locking device for securing a heat sink to an electronic device mounted on a printed circuit board.
2. Description of Related Art
It is well known that, during operation of a computer, electronic devices such as central processing units (CPUs) frequently generate large amounts of heat. The heat must be quickly removed from the electronic device to prevent it from becoming unstable or being damaged. Typically, a heat sink is attached to an outer surface of the electronic device to absorb heat from the electronic device. The heat absorbed by the heat sink is then dissipated to ambient air.
In order to keep the heat sink in intimate contact with the electronic device, a locking device is used to secure the heat sink to the electronic device. Referring to FIG. 6, a related locking device is shown. The locking device comprises two fasteners 10 for securing a heat sink 20 to an electronic device 40 mounted on a printed circuit board 30. Each fastener 10 comprises a pole 14, a head 12 located at an end of the pole 14, and a plug 16 located at an opposite end of the pole 14. A helical spring 18 circles the pole 14 between the head 12 and the plug 16. The plug 16 forms two barbs at two opposite sides thereof. In use, the plug 16 extends through a hole 24 defined in an ear 22 which extends from a side of the heat sink 20 and a hole 32 defined in the printed circuit board 30. At a bottom side of the printed circuit board 30, the barbs of the plug 16 abut against the printed circuit board 30. The spring 18 is located on the ear 22 of the heat sink 20 and presses the heat sink 20 to the electronic device 40. Therefore, the heat sink 20 is secured to and in contact with the electronic device 40. However, when detaching the heat sink 20 away from the electronic device 30, it needs a tool to converge the barbs of the plug 16 to enter into the hole 32 of the circuit board 30 and the hole 24 of the heat sink 20, which is very inconvenient. Otherwise, in order to detach the heat sink 20 from the electronic device 40, the plug 16 is cut away from the pole 14 by a tool, which causes a waste of the material and accordingly a higher cost.
What is needed, therefore, is a locking device conveniently securing\detaching a heat sink to\from an electronic device.